[PATCH] Allow matching HostName against Host entries

Iain Morgan imorgan at nas.nasa.gov
Sat Apr 13 10:42:33 EST 2013

On Fri, Apr 12, 2013 at 19:06:50 -0500, Damien Miller wrote:
> On Fri, 12 Apr 2013, Ben Lindstrom wrote:
> >
> > Is there no way to pull this information from the resolv.conf file in
> > an universal way? It really would suck having yet another location for
> > DNS search paths to maintain an environment.
> Pulling it from resolv.conf permits attacks from a rogue/hostile DHCP
> server again. The main attack here is host subsitution, if a user happens
> to have multiple servers with the same hostname but different domains names
> (e.g. "www.good.com" and "www.evil.com") then someone who can spoof the 
> suffix order could trick a ssh client that used it for canonicalisation
> to make a user connect to the wrong host completely transparently.
> It's an unlikely scenario for users on small networks, but in a large
> organisation with multiple subdomains it could be a useful trick for
> an attacker who wants to widen the set of hosts they have compromised.
> > And out of interest what would your intent be for those names who
> > still fail this qualification test?
> They would fall back to regular resolution.
> > ## Where minecraft "host" is really a fast alias to set username, an other
> > ## information to correctly log into generic.server.com without having to
> > ## hand specific them all the time.
> > Host minecraft   
> > 	User minecraft
> > 	Hostname generic.server.com 
> So you could do something like:
> Host minecraft
> 	User minecraft
> 	Hostname generic.server.com
> HostnameSuffixes foo.com ext.foo.com

I think you meant:

Host minecraft
	User minecraft
	Hostname generic.server.com

Host *
	HostnameSuffixes foo.com ext.foo.com
Iain Morgan

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